Various devices have been made to create time-varying magnetic fields for use on the human body. Generally, two types of time-varying magnetic fields have been used. The first type used an alternating current (“AC”) field that is produced when electric current is caused to alternate at any given frequency. In accordance with Maxwell's equations, a magnetic field is concurrently produced at the same frequency as the electric field. Included in this first type of time-varying magnetic field device are pulsed electromagnetic fields (PEMF) which are generated when a current is caused to move through a conductor in discrete impulses of electric charge moving in the same direction.
A second general type of device for creating time-varying magnetic fields involves physically moving a static magnetic field through space. While linear displacement is one way to accomplish this, another common method involves rotating the static magnetic field. The source of the static magnetic field is generally a permanent magnet, since an electromagnet requires considerable expenditure of energy in the form of current generation and the subsequent dissipation of unwanted heat energy.
The therapeutic uses of time-varying magnetic fields have been described and clinically evaluated in numerous literature. The more popular publications written for the general public include “Magnetic Therapy” by Dr. Ronald Lawrence and Dr. Paul Rosch, “The Pain Relief Breakthrough” by Dr. Julian Whitaker and Brenda Adderly, and “Magnetic Therapy in Eastern Europe” by Dr. Jiri Jerabek and Dr. William Pawluk. These books offer numerous references to clinical studies which purport to show the effectiveness of time-varying magnetic fields for the treatment of a multitude of chronic and acute conditions including atherosclerosis, carpal tunnel syndrome, chronic bronchitis, post-ischemic injury, edema, fractures, infected wounds, limb grafts, burns, scars, macular degeneration, etc. The lack of any substantial negative side effects is also purported for most treatments. In recent years, the general public and even the medical community have increasingly accepted magnetic therapy as an alternative treatment worthy of consideration for such conditions.
Patented devices, which utilize permanent magnets to produce a time-varying magnetic field for therapeutic purposes, include Horl U.S. Pat. No. 4,727,857; Kleitz U.S. Pat. No. 5,632,720; and Souder U.S. Pat. No. 6,001,055. All of these devices function by causing permanent magnets to rotate around a fixed axis. The magnetic field generated by each of these devices sweeps out into space in a single direction. Changing the angle of the rotation requires manual manipulation of the entire device since the axis upon which the magnets rotate is stationary. It has been observed that the angle at which magnetic flux lines cut through tissue can influence the degree of beneficial effects. What is needed therefore is a handheld device or a device capable of being attached a part of the body or to clothing, or the like, that will create a sweeping magnetic field in a multitude of directions, thus providing more complete angular coverage to the part of the body being treated with the moving magnetic field.